With the continuous development of the liquid crystal display technology, smart phones, tablets and other portable intelligent terminal with its thin and intelligent features becoming regular consumers demand. With smart phones, tablets and other portable intelligent terminal becoming increasingly popular, their use in daily life scenes are increasingly being used, for example, receive calls, Internet access, reading and entertainment, etc. At present, the power problem has limited the use time of smart phones, so in the smart phone system, the power conversion efficiency is crucial. The liquid crystal display (LCD) module as a large power of the smart phone, the power conversion efficiency is directly related to the energy consumption of the smart phone system. On LCD module, generally only input two or three power supply voltage, then converting the required various voltage through the integrated charge pump in the driving chip and obtaining the required voltage through the low dropout regulator (LDO). However, this approach is likely to be limited by the charge pump structure, usually only two or three modes for switching to obtain a fixed magnification voltage; meanwhile, with the complexity of the required voltage, and after the conversion of the charge pump and the regulation of the LDO, the power conversion efficiency becomes very low.